UPDATE: Felix Baumgartner has jumped from 23 miles up, and beaten two world records

Last week the weather cruelly thwarted Austrian daredevil Felix Baumgartner's attempt to skydive from an incredible 23 miles up and break the sound barrier on the way down.

But forecasters have given him the go-ahead for an attempt at 1.30pm UK time on Sunday – and you can watch the event live, right here on Huffington Post UK, courtesy of Red Bull Stratos.

The mission is taking place above New Mexico and will see the 43-year-old ascend to the edge of space in a capsule towed by a massive, 330ft helium balloon.

He will then leap out and hopefully leap into the record books with the highest and fastest freefall descent ever.

Felix pictured inside the capsule shortly before launch-time

The previous record for the highest freefall was set by US military pilot Joe Kittinger on 16 August 1960.

He leapt from a helium-filled balloon from 19 miles up and reached 600mph on the way down.

At about 100,000 feet above sea level, Felix Baumgartner will need to accelerate to about 690mph to match the speed of sound, known as Mach 1. Then, if he continues to accelerate and surpasses the speed of sound, he’ll be “supersonic".

To say that jumping from even higher up and plummeting more rapidly than Kittinger is a risky undertaking would be an understatement.

Felix Baumgartner soars to Earth on a test jump earlier this year

For starters, Baumgartner, also known as “Fearless Felix”, could go into a spin, haemorrhage his eyes and get a blood clot on his brain – or his blood might “boil” if his suit rips.

The Austrian may also break his neck.

But the jump has been meticulously planned over the past five years.

He’s already made two test jumps from 15 and 18 miles - and he’s using state-of-the-art kit.

For example, if he’s rendered unconscious an emergency parachute will deploy automatically.

Baumgartner has trained rigorously for the jump

Baumgartner explained that he's feeling supremely confident the jump will be successful.

He said: “The reason I believe we’re going to be successful is because we’ve put together an incredible team of experts and we have gone about this in a very carefully planned, scientific way. I didn’t want to go from zero to hero - instead we’ve done lots of tests to progress gradually, step-by-step, toward the final goal. Each test has taught us something.”

“Every test - from wearing the suit in a wind tunnel, to simulations in an altitude chamber, to jumping from airplanes, and then jumping from a balloon in the stratosphere - has been more difficult, and the success of each one has raised our motivation even higher.”

His journey down will be one that no skydiver will be familiar with.

He’ll be so high up that he won’t even have a sensation of falling, because there’s hardly any atmosphere.

Kittinger reported that his jump suit didn’t even ripple during the first few minutes of the fall.

According to Red Bull's calculations, Baumgartner will reach almost 700mph in less than 40 seconds.

Many people will wonder, of course, whether Felix really will be “Fearless” on the big day.

She told Huffington Post UK: “People who do extreme things do so because they are able to weigh up the risk and the safety factor. They can calculate the extent of the danger. Will Felix be scared? Of course - the dangers are still there – risk to health and life.

“However, the gamble is that focusing in on the goal of achieving a record will outweigh the possible death. So like a gambler – it’s weighing whether there is a greater chance of success than a risk of death. People in extreme sport examine that balance continuously.”

Dr Cohen believes that what motivates the daredevil is the challenge of redefining the limits - and simply getting a buzz.

She added: “People in extreme enjoy pushing the limits – it’s that sense of being really frightened but being really excited at the same time. It is the sense of challenge in one hand and the sense of the unknown in the other.”

Felix Baumgartner SKY Diving Attempt From Space

Felix Baumgartner SKY Diving Attempt From Space

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Felix Baumgartner

This image provided by Red Bull Stratos shows pilot Felix Baumgartner of Austria sitting in his capsule in preparation for the final manned flight of Red Bull Stratos in Roswell, N.M., Tuesday Oct. 9, 2012. Baumgartner canceled his planned death-defying 23-mile free fall on Tuesday because of high winds, the second time this week he was forced to postpone his quest to be the first supersonic skydiver. (AP Photo/Red Bull Stratos)